Finn and Jake in: The Mountains of the Moon!
by Colton M. H
Summary: Two years after Season 4, Finn is now sixteen and one of the most known heroes of Ooo. But when a meeting between the Fire Kingdom and the Candy Kingdom goes horribly wrong, it's up to him and Jake to figure out what's going on - because only they can.
1. Episode I: What Time is It?

Finn and Jake in:

The Mountains of the Moon

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**A/N: This is my first fanfic in a while and my first AT one. So be gentle in the reviews, I'm sure it sucks a lot :P You know the rest, I don't own this mang**

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EPISODE I: What Time Is It?

The hill was green and gently slopping as the clouds passed overhead, a gentle breeze carrying the seeds of dandelions across the grassland. Peacefully clouds overlapped and birds flew through them, and a tree fort stood in the distance.

"What time is it?" a 16-year-old boy yelled as he ran up and over the other side of the hill, starting down the gentle slope. He wore a blue shirt and a white hat that made it look like he had no neck, bits of blond hair coming from under the hat and down his shoulders just a little. Under his green backpack was a deep red sword made of demon's blood, and at his side ran an orange-brown dog.

"Adventure time!" the dog laughed as his legs stretched as he ran, before Jake swung up in a single leap to land on the dog's back, the dog growing to take the size of a horse.

The boy was Finn the Human, the last living human on Earth, making his home in the grass lands of Ooo. His best friend was Jake the Dog, a magical dog with the ability to stretch his body parts into any shape, form, or length.

"So where are we going today, Jake?" Finn asked as the dog slowed down as the two began up another hill, leaping over a stream.

"Lady said that the Candy Kingdom and Fire Kingdom were having a big meeting today, I think we should head there."

"Aw, man, really? It's not like there'll be anything adventurous there..."

"No, but Flame Princes will be there, buddy."

Finn's face turned red and he didn't say anything as Jake laughed. "Glob, you two are serious. Well, at least you act like you two are. How's those burns doing?"

"How'd you know about those?" Finn asked, and Jake laughed again.

"I didn't, haha."

"Jake!" Finn yelled, but sighed and laughed. "Yeah, well... whatever. So where's this meet up at?" Finn asked, Jake's running across the land of Ooo faster than just him running at normal size.

"Should be just over this hill in the Valley of Kings," Jake said as the two reached the top of the hill, and seeing a sudden cliff. "Whoa!" Jake yelled, hitting his feet into the ground as he scrambled to stop, his back legs stretching to wrap around some rocks. Finn nearly flew off of Jake but he felt Jake grab him, as they looked down and into the valley.

It had, in the past two years, become the border of the Fire Kingdom and Candy Kingdom after a series of earthquakes, forming the great valley. Now it was a rich ecosystem with a river flowing through it, birds and trees growing out of it, in the center a great island with a palace built of strange material.

"Now that looks amazing," Finn said as Jake let out a whistle, starting to climb down the cliff face with his legs stretching to stable rocks, before there was a deafening roar.

An explosion rippled out from the palace where the meeting was, Jake and Finn helpless as they watched in horror the flames spreading out, Flame Kingdom representatives fleeing as the palace began to collapse, Candy People panicking and carrying paperwork to safety as a blimp over it was quickly boarded by some figures, presumably Princess Bubblegum and the Flame King and Flame Princess.

"Jake we have to help them!" Finn yelled and Jake nodded righteously, bounding down into the valley and stretching to make his way to the island as fast as he could.

Finn leaped off of Jake as they reached the island, pulling out his sword and looking around the fiery ruins of the island and the palace, a great stone pillar falling as he raced into it. "Is anyone still inside?" Finn exclaimed as he leaped over the pillar, Jake behind him.

"Finn, slow down, bro!"

"No way, man, there might be people inside who need help!"

As Finn entered the ruins, he found the rooms empty, until bursting into a great throne room, finding Peppermint Butler on the ground, struggling to escape from the weight of the debris on him. "Peppermint Butler!"

Finn raced towards the big peppermint in a butler outfit, and the peppermint looked at him. "Finn..."

"Don't worry, we got you!" Finn announced as Jake helped him push the debris off the candy person, who just looked up at them, pulling a paper from his sleeve.

"The..."

He closed his eyes and collapsed, and Finn just sank away for a few moments.

"We didn't save him..."

"Yeah... hey, what's this paper?" Jake asked, and Finn looked towards the paper in Peppermint Butler's hand still, taking it gently.

"It's some sort of... map."

"A map? Of what?"

"I don't know, man."

Finn unfolded the map, and looked at it somewhat confused. "This map is really weird, Jake. I can't find the Candy Kingdom on it..."

"Me neither, man. What's it of?"

"I don't know... hey, that says Ooo!" Finn pointed at "OOO" before pausing.

"No, man, that's just three zeroes. Looks like it's in some kinda funky code. Maybe it has something to do with what happened?"

"I don't know..." Finn said, his voice trailing off as he folded the map in half and looked up. "But I will find out whoever, or whatever, did this and bring them a heaping serving of justice!"

Jake shrugged, before a flaming piece of wood fell through the ceiling above, reminding the two of the situation around them. "We should probably get outta here, man!"

Finn nodded, looking around one last time. "Yeah. It doesn't look like there's much for me to do now..."

"Except run!" Jake yelled as he grabbed Finn, pulling him out of the way of another falling beam. Finn ran the moment the magic dog let him go, the two racing as fast as they could to the exit, before there was a scream for help.

"Jake, we have to find whoever let out that scream!" Finn declared, Jake mumbling under his breath about how he was more concerned about not getting burned by the falling debris, and Finn started up the staircase, leaping through a doorway into a library of ancient tomes.

The door slammed shut and Jake hit against it with an audible thud, Finn realizing he had been duped by whoever had let out the scream almost instantly. "Who's there?"

"Finn, are you in there buddy?"

"Yeah, I'm fine Jake! I'll meet you outside!"

"Got it!"

Finn heard Jake leaving, and he looked around the room. "It's me and you."

A shadow seemed to move in the corner of his eye, and Finn turned to see it full-on, only finding more flames around him. And then with an _oomf!_ he was on the floor, a being holding him down. "Oh, my hero. The Slayer of the Lich, Hero of the Grasslands. Whatever would you be doing if it wasn't for your luck?"

"What the stuff, man? Who are you?"

The being laughed and turned Finn's head, while pinning his body down never the less. "Don't you recognize me, hero?" it asked softly, and Finn looked up to see the humanoid figure enshrouded in black. "Oh, my bad. It's been so terribly long... Almost seventeen years now, hasn't it?"

"I'm only sixteen, man, just let me go already, who are you!" Finn struggled and pushed, but the person on him held him effortlessly.

"In due time, hero."

Finn felt himself released, and the being was already half way across the room as he got up. "Take this!" Finn yelled, pulling his sword and lunging through the air at whoever it was. Clearly a man, but of what species or race he had no idea.

The man turned and swatted the sword from Finn's hand like it was a mere play thing, and grabbed Finn's arm with his other hand. "Ah-ah-ah, naughty boy. I thought heroes were all about honor and chivalry. I was, after all, fleeing."

"You're clearly not someone who cares about honor or chivalry," Finn protested, followed by the man laughing.

"Et, Finn? Facit honorem vere materiae?"

He threw Finn back, and turned. "When the time comes, we shall meet again, hero. Until then, farewell."

Finn lunged through the air with his foot now, but a flaming piece of debris fell right in front of him, his foot hitting it and him pushing off to avoid getting burned too badly, and he landed crouched, his hands on the ground and the man gone. "Glob, that guy was weird..." he muttered, standing up and running to his sword. "I wonder what he said..."

Finn lifted his sword and put it back, racing towards the window and looking down. "Jake!"

The dog was on the ground, looking up at the room and saw Finn, and nodded, his body stretching into a trampoline as Finn jumped, the boy falling, falling...

_Boing!_

He bounced back up just as Jake grabbed him, putting him on the ground and looking around. "Where's the person who screamed?"

"You mean you didn't see them leave?" Finn asked, and Jake shook his head. "Then where is he...?"

"Hey, Finn, you did find them right?"

"I did. Jake, whoever it was attacked me and said something – I don't know what, but he felt really odd, really familiar."

"You don't remember what he said? Was it something like 'Oh, Finn, I tricked you!'?"

"No, man. It was weird. Like, 'et finn, honorem matteriae?' I think. And then he said that we'd meet again and left."

Jake nodded his head slowly, and shrugged. "I got nothing, sorry."

"Then it looks like we have to figure out this mystery."

Finn and Jake stood there, the great building collapsing completely now, the fires in it warming the island by several degrees. "Let's go home."

Finn nodded, the two walking towards the water, Jake stretching to lift Finn onto his back as he grew, his legs stretching to the bottom of the water around them to reach the cliff face, where he'd stretch to climb it with ease.

Something about that man just wouldn't leave Finn's mind though as he looked back at the burning ruins, and he sighed. Jake didn't hear the sigh though as he whistled to himself, making his way up to the top of the cliff face once more.


	2. Episode II: The Journey of Willy

EPISODE II: The Journey of Willy

The knock on the door was what woke Finn that next morning, as he groggily got himself out of bed, finding Jake still asleep in his sprawled manner of slumber. He was partially envious that the dog was asleep still, and that he had to have been woke up. He had been having such a nice dream, except... except... well, he could remember what he hadn't liked about it, but there was something about it that had bothered him.

"Finn? Hello?" the feminine voice echoed from outside, and Finn found himself surprised at who he was recognizing the voice to. It was unlike _her _of all people to knock and ask for him, she more usually just appeared, which was rather ironic, after all she was...

"Marceline!" Finn exclaimed as he opened the door, the outside even now telling him it was early in the morning, the sun not even up yet and the sky full of stars and the moon. "What are you doing here at... whatever time in the morning it is?"

"Finn, something's going on," Marceline said, the vampire queen for once shifting nervously. "I think there's a war brewing."

Finn knew now why she was so nervous, so frightful right now. Over a thousand years ago she had seen the war that had ravaged the Earth, a war he still knew little of. He only knew that Marceline only survived as a vampire, that it had led to the fry incident with her father...

And after that, war had just put her off. Or, at least, big ones. Even now, a millennium later, there were ruins of the world before. The world she had once known. The world that he never would know, a world where he would be with other humans if only he had been born sooner.

"A war? What war, Marceline? Between who?"

"The Fire Kingdom thinks that the Ice King was responsible for the attack yesterday, and they're mustering an entire army at their borders. At least, Bonnibel said that. She's afraid the Fire Elementals might raze some of the Candy Kingdom and is threatening them with war if a single Candy Person's even touched."

"Oh, glob. So why'd you come here? I'm sure PB would be more than willing to help find peace. I mean, that whole meet-up yesterday was about forming an alliance wasn't it?"

"Look, Finn, she listens to you more than me. She might not hate me, but she doesn't exactly think I know what's going on. You know that."

Finn nodded, and sighed. "Alright, fine. I'll just go get Jake and we'll be on our way,"

Finn hurried back to their bedroom and found Jake rolled over, shaking the dog's arm gently. "Mhm... yeah... what?"

"Jake, we gotta go." Finn said, grabbing a shirt and throwing it on, grabbing his bag and his sword as well.

"Why?"

"Marceline said the Fire Kingdom is preparing for war, we have to go and talk some sense into them and PB both,"

"Fine, whatever..."

Jake got up slowly, falling onto the floor before getting up, Finn impatiently standing there. "Let's go then," Jake said, and Finn nodded, hurrying back to the door, Jake right behind him.

"Alright, Marceline, we're ready!" Finn said, the vampire queen nodding as she began to float from the tree fort, Finn and Jake quickly behind.

They arrived not too long after beginning, to find the Candy Kingdom's walls heavily guarded, barely getting in themselves even with their high status as heroes, and Marceline's from the rumors of her and the Princess being closer friends than anyone knew.

"Princess!" Finn yelled as he got into the castle, before he stopped, seeing that there were two Fire Elementals at the throne, talking to Princess Bubblegum. Both the Flame King, and Flame Princess were there, and they turned around.

"What is this Water Elemental doing here? Is this part of your ploy to stop our justice?"asked the Flame King quickly asked, concern in his voice.

"Water Elemental...?" Princess Bubblegum asked, and saw Finn. "That's a human!"

"I told you that," Flame Princess responded, the Flame King glancing at her.

"No, I'm pretty sure you never told me that you were wrong about him being a Water Elemental."

"Does it matter?" Bubblegum asked, before sighing. "Finn, what are you doing here?"

"I don't know what's going on much, I just know that Marceline-"

"The vampire," the Flame King interrupted with scorn.

"-told me that there was talk of war. And that's just not right, not until we know for sure."

"Finn, the Ice Kingdom has to have been the ones behind it... Ever since the old Ice King disappeared a year ago, they actually became dangerous," Flame Princess said, ever the aware princess. Despite being the same age as Finn, she was more knowledgeable. In likelihood, it was because her father knew she would be replacing him soon. "As sweet as it is of you to want peace, we might have to actually go to war."

"But what if it wasn't him?" Finn asked, and the Flame King sighed.

"It was and there is no one else who would do that! The other kingdoms are not violent enough, or given enough reason!" the Flame King shouted.

"But your men will damage the Candy Kingdom as they pass through, I cannot allow that without proof of the Ice King's involvement!"

"Your kingdom isn't our enemy, don't you understand that? Just because you're a scientist doesn't mean you're smarter than us!"

"And what are you, a young tramp that thinks she's hot stuff! I am smarter than you by at least ten fold!"

"What did you call me?"

The Flame King backed up a bit, the flames from the Flame Princess burning in rage.

"Princesses, please! We don't have to be like this!" Finn said, as he raced into between them. "PB wants her people safe, Flame Princess, you want to get revenge. I can dig both of those reasons," he said.

The Flame King watched with relative boredom, before he pulled out a flaming photograph of a koala. Jake stretched his head over towards it, not wanting involved, remarking on the photographs: "Nice, that one's really good."

"Thanks, haaaa."

"Then what do you think we should do?" Flame Princess asked, and Finn paused. He knew that he was most likely ruining his chances with her by opposing her, but things weren't necessarily going that well anyways.

"Check this map, ladies," he said as he pulled from his pocket the map he had got at the ruins. "I got this at the meet up, I got there at a bad time. I don't know what it is, but I think that it's something to do with what happened," he said, and Princess Bubblegum got up from her throne to walk over and look at it.

"What would a map have to do with it?" the Flame King demanded, Flame Princess looking at him with a glare of 'he knows what he's talking about' and then back at the map, the king letting his daughter take care of it over him.

"This is absolutely fascinating! Where indeed is this... and zero-zero-zero... interesting indeed!"

"It reminds me of the stories I heard about the ancient continent of Afrocuh..."

"What's that, Flame Princess?" Finn asked, and the Flame Princess took a step back from the map to look at him for a second.

"Finn, you haven't heard of Afrasia?" she asked, and he shook his head.

"Neither have I," Princess Bubblegum said with a bit of surprise in her voice. "It must be a Flame Kingdom thing."

"Oh. Well... they say that before the Mushroom War so long ago, there was a continent named Afrasia, and a river there flowed backwards, out of these great mountains... the Mountains of the Moon."

"That sounds really intense, and you think this is that map?" Finn asked, Flame Princess nodded.

"Are those...?" Princess Bubblegum asked, taking the map from Finn and turning it slightly. "They are. I recognize the language, it's an archaic form of ours. That says 'The Mountains of the Moon'."

"Where is this supposed to be from here?" Finn asked, and Flame Princess looked at the map, moving her finger over it as if doing some nautical travel calculations.

"It should be to the west, but I can't see myself going... I'm not fond of boats."

"I'd protect you from the ocean, though, Flame Princess," Finn said, and Flame Princess put her hands on her hips.

"If the boat even began to sink, I'd be dead."

"O-oh... yeah, that's true..."

"And I have a kingdom to govern. It looks like you and Jake will be going alone."

"I'm going too," Marceline said, stepping into the conversation then. "I haven't been outside of Ooo since... since along time ago. I want to see it again at least once."

"Alright then. Finn, Jake, Marceline, good luck."

"Thanks, Bonnibel, for letting me," Marceline said, and Princess Bubblegum gave her a disapproving look from the usage of her first name. "When do we leave then?"

"I'm ready as soon as we have a boat," Finn said, Jake walking over to them. "Jake, we figured out where the map is!"

"Cool! So are we going there or something?"

"Yeah, man. Soon as a boat's ready."

"There's one I'm sure, Finn. Just tell them I sent you," she said, and looked at Marceline. "Be safe, okay?"

"We will be," Marceline said, interrupting Finn a he started to say he would be.

Flame Princess held her hands nervously, and Finn walked towards her. "I'll figure things out, princess."

"You'll be safe?"

Finn nodded.

"And..."

"And...?"

"And come... back to me...?"

Finn blushed, and nodded. "I will, Flame Princess. I swear on it."

She hugged him and he winced, the pain of the burns from her flaming body coursing through his body, but he returned the hug nonetheless. He pulled away as the smell of smoke came, and the burns on him were thankfully less than he had expected, it was just his clothes.

"Let's go, yeahhhh!" Jake said, as he started walking, his legs and arms waving like water. "Let's go to some mountains on the moon, aw yeaahhh!"

Finn waved to Flame Princess as Marceline passed him on the way to the door, and he turned, hurrying behind the two friends of his.

"Wait up guys, don't leave me behind!" he laughed, the two pausing as he caught up. "Let's get going!"

"What time is it?" Jake laughed as he stretched and grew, the human jumping on his back and pulling a sword from his bag, grinning as the vampire floated besides the magic dog, holding an umbrella to block the rising sun beams from hitting her.

"Adventure time!"

And so began their adventure, to the Mountains of the Moon.


End file.
